The present invention relates to separation of a prefix assignment from generation of an interface identifier in a Dynamic Host Configuration Protocol (DHCP) v6 server, and to generation of a dynamic IP address. The invention may be understood by reference to the documents cited by the present disclosure, all of which are incorporated herein by reference.
A DHCPv6 server is assumed to be responsible for assignment of an integrated or combined internet protocol (IP) address that includes two portions, i.e. a prefix and an interface identifier. The operation of address assignment by a DHCPv6 server is described in [Request for Comments (RFC)3315]. A client uses a Solicit message to identify the DHCPv6 server that is configured to assign IP addresses. The DHCPv6 server sends an Advertise message in response to announce the availability of the DHCPv6 server to the client. The client then uses a Request message to request an IP address. The DHCPv6 server then returns the IP address in a Reply message. The details of the two portions of the IP address, i.e. a prefix and an interface identifier, are described in [RFC4291].
A prefix assignment may be separated from generation of interface identifier. For example, [RFC3633] describes Prefix Delegation options that provide a mechanism for automated delegation of IPv6 prefixes using the DHCPv6. This mechanism is intended for delegating a long-lived prefix from a delegating router to a requesting router. However, the practice of separating prefix assignment from interface identifier assignment is only used for routers, but not for hosts in [RFC3633].
There are situations when a separation of a prefix assignment and a generation of an interface identifier is desired. Currently, a DHCP server may not be able to generate an interface identifier for a host. Hence, there remains a need for developing a method to formulate an IP address from separated prefix and interface identifier that may be generated to meet the need of security or privacy.